The present invention relates to an apparatus and technique for fabrication of a variety of miniature structures such as semiconductor chips, optical, chemical, biological, environmental, physical, electromagnetic detectors/sensors, mechanical and electromechanical elements and actuators, antennae, different electronic components, as well as vias, channels, guides, etc.
More particularly, the present invention relates to an apparatus and technique for fabrication of miniature structures where the Direct Write (additive process) and micromachining (subtractive process) are carried out with and in the same fabrication tool by means of synchronous control and manipulation of elements of the fabrication tool.
Still further, the present invention relates to an apparatus having a control mechanism which operates the fabrication apparatus in either of two modes of operation: xe2x80x9cmaterial transferxe2x80x9d and/or xe2x80x9cmaterial removalxe2x80x9d modes of operation. The additive process, such as Laser Forward Transfer, or Laser Induced Forward Transfer methodologies are carried out during the xe2x80x9cmaterial transferxe2x80x9d mode of operation to deposit materials on the substrate surface and to create additive structures such as various detectors, sensors, actuators, semiconductor chips, etc. In the xe2x80x9cmaterial removalxe2x80x9d mode of operation a subtractive process is carried out resulting in a material removal from the workpiece by means of ablation, evaporation, melting, cutting, drilling, etc. of the workpiece, thus creating channels, guides, vias. During the xe2x80x9cmaterial removalxe2x80x9d mode of operation, the fabrication tool performs as a micromachining workstation so that the substrate with the structures previously created thereon during the xe2x80x9cmaterial transferxe2x80x9d mode of operation may be diced or excised into individual subunits, and can be trimmed or shaped to precise specified values.
Further, the present invention relates to an apparatus and method in which a controllable energy or energetic beam is directed towards a substrate where a material carrier element having a deposition layer formed thereon is displaceably positioned in spaced relationship with the substrate. A control unit synchronously manipulates the material carrier element and the energy beam in accordance with the type of the structure to be manufactured.
In this manner, in a xe2x80x9cmaterial removalxe2x80x9d mode of operation, the control unit displaces the material carrier element away from interception with the energy beam so that the energy beam impinges onto the surface of the substrate in a predetermined manner and disintegrates the surface material of the substrate to a predetermined depth.
Further, in the xe2x80x9cmaterial transferxe2x80x9d mode of operation, the control mechanism displaces the material carrier element into a position intercepting the energy beam so that the energy beam modifies the deposition layer on the material carrier element, and causes transfer and deposition of the deposition material onto the surface of the substrate in accordance with a predetermined pattern.
In both modes of operation, for performing patterned removal of the material from the surface of the substrate or patterned deposition of the material onto the surface of the substrate, the control unit changes the relative position between the energy beam and the substrate in a patterned manner.
Miniature structures having electrical components are widely used in a variety of consumer and industrial items, such as TV sets, radios, cars, kitchen appliances, computers, etc.
Due to the need for such miniature structures, such as computer chips, and other mechanical and electromechanical elements, different manufacturing processes have been developed.
Methodologies of manufacture include, among others, additive Direct Write processes such as Laser Forward Transfer (LFT), Matrix Assistant Pulse Laser Evaporation, or Laser Induced Forward Transfer (LIFT) techniques, well-known to those proficient in the miniature structure fabrication art.
In the course of these techniques, a material from the deposition material source is transferred towards a substrate and is deposited thereon in accordance with a predetermined pattern either to manufacture a single structure or a plurality of structures on the same substrate. Simultaneously, a subtractive process is employed using laser energy to ablate, evaporate, melt, cut, drill, or otherwise remove material from the workpiece. In this manner, channels, guides, or vias can be laser milled or drilled. Additionally, a substrate with a plurality of structures may be excised into individual subunits, trimmed or shaped.
Although both additive and subtractive processes are well-developed and known in the miniature structures manufacturing industry, there is a drawback which still exists resulting from the necessity to. transfer the substrate with deposited structures thereon from one area (where the additive Direct Write process takes place) to a micromachining workstation, or conversely, from a micromachining station where the surface cleaning takes place to a material deposition area.
During this substrate transfer from one location to another, physical damage to the workpiece may be found, the workpiece may be contaminated, or areas exposed during surface cleaning may be reoxidized, thus substantially reducing yield of the high quality devices.
Additionally, transfer of the workpiece from one location to another requires additional labor effort and precaution to protect the workpiece from being damaged or polluted, thus further increasing the costs and complexity of the manufacturing process and equipment.
Accordingly, despite the use of the existing manufacturing equipment and techniques for fabrication of miniature structures, a long felt need has arisen and exists for equipment and techniques free of the disadvantages of the prior art.
It is therefore an object of the present invention to provide a tool and method for fabrication of miniature structures which carry out both additive and subtractive processes in and with the same apparatus.
It is a further object of the present invention to provide an apparatus for fabrication of miniature structures in which a control unit operates the apparatus in either a xe2x80x9cmaterial removalxe2x80x9d and/or xe2x80x9cmaterial transferxe2x80x9d mode of operation. In this manner by using the same apparatus, either a deposition of a material on the surface of the substrate can be effected or removal of the material from the surface of the substrate can be performed.
It is an object of the present invention to provide an apparatus for manufacturing of miniature structures in which during a xe2x80x9cmaterial removalxe2x80x9d mode of operation, the control unit permits direct impingement of the energy beam onto the surface of the substrate so that the energy beam xe2x80x9cscansxe2x80x9d the surface of the substrate in a patterned fashion and removes material from the surface of the substrate in accordance with the type of structure to be created.
An additional object of the present invention is to provide an apparatus and method in which, during the xe2x80x9cmaterial transferxe2x80x9d mode of operation, the control unit moves a material carrier element into an intercepting path with the energy beam. When the energy beam impinges on the deposition layer on the material carrier element such causes transference of the material contained in the deposition layer to the surface of the substrate and the material is deposited thereon in a patterned manner in accordance with the type of the structure to be created.
It is still a further object of the present invention to provide an apparatus for fabrication of miniature structures created by equipment which includes a source for the energetic beam, a substrate, a material carrier element having a deposition layer thereon, and a control unit which synchronously manipulates the material carrier element and the energetic beam in accordance with the type of the structure to be created and the type of operation (additive or subtractive) to be performed. In carrying out an additive process, the material carrier element is displaced into interception with the energy beam, and the relative disposition between the energy beam and the substrate is changed in a patterned fashion. In carrying out a subtractive process, the material carrier element is displaced away from interception with the energy beam, and the relative disposition between the energy beam and the substrate is controlled in a patterned fashion.
In accordance with the present invention, an apparatus for fabrication of miniature structures includes a substrate, a source of energy capable of generating an energetic beam directed towards the substrate, a material carrier element displaceably disposed in a gap formed between the source of energy and the substrate, a deposition layer supported on the surface of the material carrier element facing the substrate, and a control unit operatively coupled to the source of energy (and/or to the substrate) for regulating parameters of the energy or energetic beam. The control unit controls the relative interposition between the energy beam and the substrate in accordance with a predetermined pattern. The control unit is also operatively coupled to the material carrier element for manipulating the same within the gap formed between the source of energy and the substrate by moving the material carrier element either into a position corresponding to the xe2x80x9cmaterial removalxe2x80x9d mode of operation or to a position corresponding to the xe2x80x9cmaterial transferxe2x80x9d mode of operation.
In the position corresponding to the xe2x80x9cmaterial removalxe2x80x9d mode of operation, the material carrier element is displaced away from intercepting the energy beam, in order that the energy beam has a direct access or clear path to the substrate and impinges upon the surface of the substrate at a predetermined location. This causes disintegration of the material of the surface of the substrate to a predetermined depth and subsequent removal of the material from the .predetermined location on the substrate.
When the material carrier element is in the xe2x80x9cmaterial transferxe2x80x9d mode of operation, the material carrier element intercepts the energy beam which impinges upon the material carrier element, thus causing modification of the deposition layer at a predetermined location or point of impingement. The material contained in the deposition layer is then transferred from the material carrier element to the substrate for deposition thereon in accordance with a predetermined pattern.
In order to remove material from the substrate or to deposit material onto the substrate, the control mechanism performs control of the source of the energy beam by changing relative disposition of the energy beam with respect to the substrate, by regulating size and shape of the cross-section of the energy beam, and by regulating a fluence or movement of the energy beam.
Although different energy beams may be used in the apparatus of the present invention such as laser beams, ion beams, and electron beams, a pulsed UV excimer laser is thought to be preferred among others.
Preferably, the deposition layer on the material carrier element includes a material to be deposited (powder, metal, composite, alloy, ceramic, etc.), and/or a vaporizable substance.
Further, the present invention includes a method for fabrication of miniature structures, which includes the steps of:
providing a fabrication tool which carries out both additive and subtractive processes. The apparatus includes a substrate, a controllable energetic beam directed towards the substrate, a deposition layer supported on a material carrier element, and a control unit operating the fabrication tool in either a xe2x80x9cmaterial removalxe2x80x9d and/or a xe2x80x9cmaterial transferxe2x80x9d modes of operation. In the xe2x80x9cmaterial removalxe2x80x9d mode of operation, the control unit displaces the material carrier element away from intercepting the energy beam and controllably changes the relative position between the energy beam and the substrate, thereby removing disintegratable material from the surface of the substrate in accordance with a predetermined pattern.
In the xe2x80x9cmaterial transferxe2x80x9d. mode of operation, the control unit maintains the material carrier element in an interception path with the energy beam and controllably changes the relative position between the energy beam and the substrate, thereby transferring material contained in the deposition layer onto the substrate for deposition thereon in accordance with a predetermined pattern.
The xe2x80x9cmaterial removalxe2x80x9d mode of operation may then be further initiated after the xe2x80x9cmaterial transferxe2x80x9d mode of operation for cutting the substrate into separate units with each having a created structure thereon and trimming the structures to required dimensions. In cleaning the surface of the substrate before the Direct Write process is performed, the xe2x80x9cmaterial removalxe2x80x9d mode of operation is initiated prior to the xe2x80x9cmaterial transferxe2x80x9d mode of operation.
In the xe2x80x9cmaterial removalxe2x80x9d mode of operation, electrical vias, micromachined channels, guides, and other contours may be created. In the xe2x80x9cmaterial transferxe2x80x9d mode of operation, a variety of electrical components, such as semiconductor chips, sensors, detectors, and other components, may be fabricated.